This invention relates to "chaff" payload dispensing apparatus. More specifically, but without limitation, the present invention relates to an apparatus for automatically dispensing a chaff payload and/or other radar counter-measure materials from an aircraft to confuse an observer at a radar receiving apparatus thereby eliminating the possibility of the chaff dispensing aircraft and the following aircraft being separately silhouetted on a receiving radar screen.
The term "chaff" used herein generally refers to radar interfering means such as the usual type of foil ribbons as well as similar means, for example, metal covered glass fibers and the like. Devices of this type in question are known and used for spreading chaff clouds from airplanes directly and by other means. Such a chaff cloud normally consists of a very great number of ribbons or fibers of different lengths which form dipoles of different lengths. Depending on the length of the dipoles, the chaff clouds will interfere at frequency bands used for radar reconnaissance, homing missiles and similar objects. Chaff clouds are also employed for the purpose of tracking high altitude wind currents. In addition, other radar counter-measures may be dispensed utilizing the present invention.
In the past, chaff has been dispensed using a variety of apparatus. One such device utilizes a chaff carrying rocket with a mechanical timer which triggers an electronic activator at a predetermined interval after launch. The activator explodes and releases a locking mechanism which separates the rocket and disperses the chaff. Such a device is shown in U.S. Pat. No. 3,143,965. Another such device utilizes a chaff carrying rocket with a burning fuse of predetermined burn time to explode the rocket and dispense the chaff. Such a device is shown in U.S. Pat. No. 3,137,231. A passive device shown in U.S. Pat. No. 3,500,409 utilizes a chaff container with a removable lid having a drag lip for catching the wind and separating the lid from the container. As the lid separates from the container, a rope is withdrawn to dispense the chaff in the container. Still another device includes a chaff carrying outer case with a timer for delaying the deployment of a parachute after release. The parachute pulls a canister from the outer case wherein an explosive charge is activated to explode the canister and release the chaff. An example of such a device is shown in U.S. Pat. No. 3,242,810. Other devices are shown in U.S. Pat. No. 3,068,472 and U.S. Pat. No. 4,134,115.
Modern attack aircraft are most vulnerable to enemy defenses during a conventional bomb attack run when the pilot must maintain the aircraft in a straight path delivery. In addition, the pilot is so preoccupied with the many complexities of delivering and directing the bomb payload to the target that manipulating controls to dispense "chaff" clouds is very difficult. Additionally, existing pilot activated chaff dispensers carry a limited amount of chaff which oftentimes is already depleted prior to reaching the target area. Accordingly, it is highly desirable to be able to automatically release additional "chaff" during the bombing run without the need for pilot intervention. In addition, the "chaff" payload dispensing apparatus must be sufficiently simplistic, to enable ground crew personnel to "load in" different arrays of chaff and other radar counter-measures. It is therefore essential that the apparatus be highly simplistic and easily manipulated by ground crew personnel.